L48 Front Hydraulic Pump Coupling Shaft

[Zippy Zoom]

Several years ago the composite plates that connect the coupling shaft to the engine and front hydraulic pump on my L48 failed as sis their replacements. Some kind soul on this board directed me to the factory solution that my local dealer hadn't heard of: a shaft with CV joints on either end to replace the entire assembly. Now THAT shaft has failed after many hours of service.

My local dealer says the part #32771-99702 - "KIT JOINT, F PUMP" is not available and is back ordered until next spring or later. If it was available this small shaft lists for about $725! I found 2 national parts houses that claim to have it in stock, but when pressed don't actually have it.

Meanwhile I've got a tractor sitting in an awkward spot with no way to lift the front bucket. Any suggestions?

Zippy

 

[North Idaho Wolfman]

Several years ago the composite plates that connect the coupling shaft to the engine and front hydraulic pump on my L48 failed as sis their replacements. Some kind soul on this board directed me to the factory solution that my local dealer hadn't heard of: a shaft with CV joints on either end to replace the entire assembly. Now THAT shaft has failed after many hours of service.

My local dealer says the part #32771-99702 - "KIT JOINT, F PUMP" is not available and is back ordered until next spring or later. If it was available this small shaft lists for about $725! I found 2 national parts houses that claim to have it in stock, but when pressed don't actually have it.

Meanwhile I've got a tractor sitting in an awkward spot with no way to lift the front bucket. Any suggestions?

Zippy

You can manually jack up the loader arms and block the cylinders to get it moved.

I would then hit up some local small machine shops and see what they think.

 

[Roadworthy]

You have a small shaft with cv joints on each end. Can these joints not be replaced with automotive cv joints or U joints? Just a thought.

 

[rbargeron]

If you still have the old shaft and parts, you could get running again making some aluminum or steel drive disks with bolts & elastic stop nuts left a half-turn loose so the assembly can run without binding.

A local repair/machine shop could make up a new shaft with 2 inexpensive flex couplings. The pump and engine are both hard-mounted so all the shaft needs is decent torsional strength and a bit of alignment flex. Two-row chain couplings are inexpensive, easy to adapt, and long-lasting. Kubota used them on earlier models. Jaw-type couplings are cheap too and compact.

 

[Zippy Zoom]

I'm a pack rat from way back, but I'm pretty sure the old shaft went away in a cleanup-the-barn frenzy a few years back (why did I save this stupid thing????). I'll probably end up going to a machine shop with a pile of parts to see what they suggest. Sigh....

Zippy

 

[rbargeron]

Looking at the parts diagram above, bring parts 50 and 70 with you and a good measurement of the installed distance between them. Also determine how big the coupling diameters can be and location of any tight spots. My L48's pump drive is working fine - let me know if you need any info from it. Take care, Dick B.

 

[Zippy Zoom]

After a few go rounds with a few machine shops, I finally got a shaft that fit and installed it. It now happily spins the front hydraulic pump, but I still have no Hydraulics- not even to the backhoe which I did have before installing the shaft. Before I go crazy and replace the pump (I do have a spare), does anyone have a suggestion?

Looking at past threads I see the possibility that I may have lost prime to the hydraulic pump but no suggestions on how to fix this. Fluid levels are good, fluid is clean appearing and fluid and filters were changed about 100 hours ago. Super UDT was used. I'm willing to drain and replace filters and fluids, but I hate throwing parts and $ at it without an understanding of the problem.

Suggestions?

 

[North Idaho Wolfman]

After a few go rounds with a few machine shops, I finally got a shaft that fit and installed it. It now happily spins the front hydraulic pump, but I still have no Hydraulics- not even to the backhoe which I did have before installing the shaft. Before I go crazy and replace the pump (I do have a spare), does anyone have a suggestion?

Looking at past threads I see the possibility that I may have lost prime to the hydraulic pump but no suggestions on how to fix this. Fluid levels are good, fluid is clean appearing and fluid and filters were changed about 100 hours ago. Super UDT was used. I'm willing to drain and replace filters and fluids, but I hate throwing parts and $ at it without an understanding of the problem.

Suggestions?

Cracking a pressure line fitting will sometimes assist in priming a dry pump.

Also check the suction side for any seeping leaks that could be sucking in air.

 

[G.rid]

That's great that you got the shaft fixed but where's the pictures?

As far as no flow, my first thought was low oil.